Vibrational energy-harvesting performance of bio-sourced flexible polyamide 11/layered silicate nanocomposite films

摘要

The energy-harvesting efficiency of melt processed polyamide 11 (PA11) films and its nanocomposites have been investigated as a function of filler type and content. In the present work, nanoclays have been used as structural modifiers in a PA11 matrix. The nanocomposites were prepared using layered clays, Cloisite 20A, 10A, and Na+, by extrusion process through varying the filler content, 1, 2, 4, and 5 wt.%. The crystalline structure of these nanocomposites has been studied by X-ray diffractometer. It has been demonstrated that layered silicates are not significant for the structural quality of the obtained nanocomposites. Regarding the interlayer peak of different clays, it has also been revealed that Cloisite 20A is partially exfoliated, whereas 10A and Na+ are totally exfoliated in the PA11 matrix. From mechanical and dynamic mechanical analyses, it was found that the addition of layered silicates results in an increase in mechanical properties. The piezoelectric strain coefficient d(33) and dielectric constant epsilon(R) have been measured on polarized films at ambient temperature. Among all the prepared nanocomposites only Cloisite Na+-loaded PA11 nanocomposites showed the best piezoelectric constant. This observation showed that piezoelectric constant not only depends on the crystalline phases but also on the nature of the filler. Cloisite Na+ is more polar than other modified clays and high polarity leads to a better polarization response. A specific method for the quantification of energy vibration recovery has been developed for these nanocomposites. The capabilities of vibrational energy recovery were studied on PA11 loaded with Cloisite Na+.